<!DOCTYPE html>
<html lang="en">
<head>
	<meta charset="UTF-8">
	<title>背景</title>
	<style>

		.box1{
			width:100px;
			height:100px;
			background-image:url(images/1.jpg);
		}
		.box2{
			width:500px;
			height:300px;
			background-image:url(images/2.jpg);
			background-size: 
		}
		.box3{
			width:50px;
			height:30px;
			background-image:url(images/2.jpg);
			background-size: 
		}

	</style>
</head>
<body>
	<div class="box1">
		
	</div>
	<div class="box2">
		
	</div>
	<div class="box3">
		
	</div>
</body>
</html>